Rap collaborations start, flourish and dramatically burn out once every few months. Young Thug and Rich Homie Quan’s transcendent mixtape Rich Gang: Tha Tour Pt. 1 is less than four years old, but it’s a landmark release, churning out stylistic offspring since it first dropped. The latest branches on the Rich Gang tree are Lil Baby and Gunna, who have paired up for an upcoming mixtape. The Atlanta rookies sound like embryonic reptiles that were born out of the Young Thug-indebted primordial ooze, with a dash of Quan’s genome thrown in for good measure. In short, the duo’s chemistry on their new song, “Drip Too Hard,” is contagious and undeniable.

Baby tends to use his flow as a brutal, tumbling tool — it’s meant to bludgeon a beat into submission. Gunna’s delivery, alternately, searches for a smooth undercurrent to move in. A common complaint from the uninitiated is that the duo sound too similar to each other, but that’s a shortsighted critique. The brilliance of a song like “Drip Too Hard” is its unstoppable momentum, which comes from the pair’s reaching a middle point from their own stylistic approaches. Baby’s hook effortlessly flows into Gunna’s verse, and back again. It’s hypnotic enough that its two minutes go by in a flash.

There are a few pointers out there that indicate Baby and Gunna have already been anointed as rap’s next stars out of Atlanta. Quality Control — the same label that signed Migos and Lil Yachty — is shepherding Lil Baby to mainstream success. His recent single, “Yes Indeed,” featuring a guy named Drake, went to Number Six on the Billboard Hot 100 in May. In a Complex interview, Baby described how he even he was surprised the Toronto rapper hopped on the record.

“When it was time for [Harder Than Ever] to get turned in, Coach K called and told me that that record was going on my album,” Baby explained. “Up until maybe four or five days before the deadline, I didn’t know that was going on my album. I was amazed.”

Similarly, Gunna is signed to Atlanta royalty through his deal with Young Thug, but has spent the past few years climbing out of his mentor’s shadow with solid releases like his Drip Season mixtape series, and a standout appearance on “Yosemite,” on Travis Scott’s blockbuster Astroworld.

Gunna and Baby’s collaborative project, Drip Harder, is set to be released later this month.